1. Field of the Invention
The present invention relates to semiconductor fabrication technology; and, more particularly, to a capacitor having a metal-oxide-metal (MOM) structure.
2. Description of Related Art
A capacitor embedded in a semiconductor chip is classified into a metal-insulator-metal (MIM) structure, hereinafter, referred to as an MIM capacitor, and a metal-oxide-metal (MOM) structure, hereinafter, referred to as an MOM capacitor. The MIM capacitor requires an additional process to individually form an upper electrode, a lower electrode and an insulator while the MOM capacitor does not need an additional process because it uses a parasitic capacitance between interconnections formed during a back-end of line (BEOL) process.
However, since the MOM capacitor uses the parasitic capacitance subsequent to the BEOL process, it is required to increase a size of the MOM capacitor to gain a high electrostatic capacitance in a unit. Consequently, active devices occupy a large area in a semiconductor chip inevitably, resulting in production cost.